South Australian Centre Alliance senator Stirling Griff's proposed legislation would force political parties to offer an unsubscribe function to unsolicited messages.

The bill was introduced on the same day the media and communication watchdog revealed almost 11,200 spam complaints were made in the past financial year.

The issue returned to the spotlight when unsolicited political text messages from MP Craig Kelly resulted in hundreds of Australians lodging official complaints.

Registered political parties are exempt from a large number of requirements under the Spam Act, which has been used to fine businesses in Australia for sending unsolicited text messages and emails.

Woolworths was fined more than $1 million for sending commercial emails without consent and Kogan Australia was fined $310,000 for sending commercial emails without an unsubscribe option.

The Australian Communications and Media Authority undertook nine investigations into whether unsolicited messages broke the Spam Act in the last financial year, triple the number of investigations compared to the previous year.

There were a further 14 investigations into whether "do not call" register laws were breached.

The ACMA issued four infringements, six enforceable undertakings and eight formal warnings across both investigation categories.

One proceeding remains before the Federal Court.

Australian Associated Press